diff --git a/data/Dockerfiles/netfilter/server.py b/data/Dockerfiles/netfilter/server.py
index 4b80851c..88fc5f25 100644
--- a/data/Dockerfiles/netfilter/server.py
+++ b/data/Dockerfiles/netfilter/server.py
@@ -100,6 +100,7 @@ def refreshF2bregex():
     f2bregex[6] = '([0-9a-f\.:]+) \"GET \/SOGo\/.* HTTP.+\" 403 .+'
     f2bregex[7] = 'Rspamd UI: Invalid password by ([0-9a-f\.:]+)'
     f2bregex[8] = '-login: Aborted login \(auth failed .+\): user=.+, rip=([0-9a-f\.:]+), lip.+'
+    f2bregex[9] = 'NOQUEUE: reject: RCPT from \[([0-9a-f\.:]+)].+Protocol error.+'
     r.set('F2B_REGEX', json.dumps(f2bregex, ensure_ascii=False))
   else:
     try:
diff --git a/docker-compose.yml b/docker-compose.yml
index 029fbc24..458e48b8 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -420,7 +420,7 @@ services:
             - acme
 
     netfilter-mailcow:
-      image: mailcow/netfilter:1.42
+      image: mailcow/netfilter:1.43
       stop_grace_period: 30s
       depends_on:
         - dovecot-mailcow